What is Virtual Fence? Basics of a Virtual Fencing System

In Arizona and other western states, ranchers and land managers rely on thousands of miles of permanent wire fencing to manage livestock on rangelands. Patented in 1874, this type of fencing has been widely used to control the timing and distribution of livestock grazing across the landscape (Ray and Schamel 1997). When combined with modern rangeland management principles, the use of wire fencing has led to improved rangeland condition in many places by aiding in the application of grazing systems (Holecheck et al. 2011). However, permanent fencing also results in significant management limitations. Wire fencing can fragment landscape connectivity, pose a risk to wildlife, and can be a major financial investment for ranchers and land management agencies to establish and maintain (Jakes et al. 2018). Additionally, permanent fences provide little to no flexibility to rapidly change pasture size, manipulate grazing distribution, or avoid areas of high use or sensitive habitat within a pasture. As a result, there are constraints on the use of permanent fences as a tool for managing riparian health, post-fire vegetation recovery, or improving livestock distribution. Precision livestock management technologies have emerged in recent years to address these limitations and increase management flexibility and adaptive capacity to respond to changing environmental conditions as part of a larger grazing management system that balances economic and ecological outcomes (Trotter 2010; di Virgilio et al. 2018; Lima et al. 2018). Virtual fencing is one such technology.